The proposed research seeks to enhance our understanding of the underpinnings of mathematical performance by hearing and deaf students. It follows from recent findings concerning the development of mathematical abilities in hearing children and empirical research and achievement data indicating that deaf students lag behind hearing age- mates in mathematical proficiencies. Of particular interest will be possible interactions among language fluencies, sociocultural expectations and motivation, specific cognitive factors (e.g., working memory, executive functioning), and metacognitive functioning related to mathematics. The project will include seven complementary studies that address five primary goals: (1) Characterization of the development of emergent mathematical skills by examining the extent to which early numerical skills provide the foundation for later conceptual understanding of mathematics, (2) assessment of the contribution of developing cognitive resources to mathematical achievement through examination of quantitative and qualitative individual differences in students aged 5-25 years, (3) determination of how student and family characteristics and perspectives on the importance of mathematics achievement interact with cognitive skills in the development of mathematical abilities, (4) determination of how language fluency and the mode of language use by deaf students (speech or sign language) contribute to mathematical proficiency, and (5) exploring means of optimizing learning of mathematics in the classroom. This project will utilize standardized assessment tools for examining mathematics achievement, laboratory tasks that tap simple numeric and cognitive abilities necessary for mathematics performance, and surveys examining social- motivational perspectives of students and their parents. Simulated classrooms will be used to explore supports for and barriers to mathematics learning by deaf students who vary in their communication fluencies. Proposed studies will take advantage of a unique collaboration involving settings and investigators in the United States and the United Kingdom. The proposed research will provide the first empirical evaluation of interactions among social-motivational (including cultural), language, and cognitive abilities both developmentally and at various ages. Comparison of deaf and hearing students and involvement of the same children and college student participants in multiple studies will yield information concerning the locus of mathematics learning disabilities as a more complete understanding of factors affecting the development of mathematical proficiency. PUBLIC HEALTH RELEVANCE: The proposed research will explore the foundations of mathematics performance among hearing and deaf children and young adults. The project will provide the first empirical evaluation of the ways that language, social-motivational factors, and cognitive abilities in direct and affect mathematics performance of these students at various ages. Results will be informative with regard to the mathematics learning difficulties encountered by many deaf students, but also by hearing students in a variety of academic settings.